Bump workspace to edition 2024

- edition = "2024" in the workspace manifest and rsdosedit
- extern blocks must be unsafe: interrupts.rs ISR stubs -> unsafe extern "C"
- #[no_mangle] -> #[unsafe(no_mangle)] (efi_main, isr_dispatch)
- One missed static-mut read in free_list_insert wrapped in an explicit
  unsafe block (edition 2024 removed the implicit unsafe context inside
  unsafe fns)
- rustfmt reflows for 2024: nested if-lets become let-chains, imports
  re-sorted, rsdosedit help-screen box rows wrapped

No codegen-affecting changes. Validated: cargo check/clippy/fmt clean
(host + uefi target), make test-disk PASS, editor round-trip PASS.

1 files changed, 1 insertions, 7 deletions

diff --git a/rsnix/src/vt.rs b/rsnix/src/vt.rs
index 2cfb0f3..709ea71 100644
--- a/rsnix/src/vt.rs
+++ b/rsnix/src/vt.rs
@@ -224,13 +224,7 @@ fn put_byte(b: u8) {
 }
 
 fn param(i: usize, default: usize) -> usize {
-    unsafe {
-        if i < NPARAMS {
-            PARAMS[i]
-        } else {
-            default
-        }
-    }
+    unsafe { if i < NPARAMS { PARAMS[i] } else { default } }
 }
 
 /// Place a printable glyph at the cursor and advance (wrapping/scrolling).